Transformer construction



Patented Mar. 13, 1951 TRANSFORMER CONSTRUCTON Edwin A. Link, Milwaukee,Wis., assigner to McGraw Electric Company, a corporation of DelawareApplication September 13, 1948, Serial No. 49,023

2 Claims.

This invention relates to transformer constructions.

In constructing a transformer it is the usual practice to provide aplurality of ducts to provide for the circulation of oil or othercooling medium. The practice heretofore followed is to place all of theducts of a series in a single circumferential layer so that there are aplurality of adjacent ducts all located in this single circumferentiallayer. Of course, as many other series of ducts may be provided in theprior constructions as necessary, but in each instance each series is ina single circumferential layer.

In the prior constructions it is a relatively easy matter to accidentlydisplace some of the spacing members which hold the successive layersapart and thereby form the duet, and when this occurs blocking of theadjacent ducts results. Also it is apparent that there is a considerableamount of vibration in all transformer constructions and loosening ofthe spacing members may occur, even after the transformer has beeninstalled.

This invention is designed to overcome the above noted defects andobjects of this invention are to provide a novel form of transformerconstruction in which the cooling ducts for the circulation of thecooling medium are formed in different circumferential layers andpreferably only a pair of ducts is formed in any one layer by the use ofa single spacing member of wood or other insulating material, althoughthe invention in its broader aspect contemplates the provision of asmany pairs of ducts in any given circumferential layer as desiredprovided the winding immediately embracing or surrounding a spacingmember becomes tangent to the underlying layer prior to the positioningof another spacing member, so that each spacing member is tightly andrmly bound by a layer of the winding and the winding surrounding thesingle spacing member is drawn tightly into tangential engagement withthe underlying layer and thus firmly binds and holds the spacing memberagainst accidental displacement either during assembly and handling orafter installation.

A further feature of this invention is to provide pairs of coolingducts, each pair being obtained by the use of a single spacing memberand to space both peripherally and radially the successive series ofducts to thus secure the most effective cooling for the least number ofcooling ducts.

A further object is to provide a construction for the cooling ducts oftransformers and the like which may be most easily produced.

An embodiment of the invention is shown in the accompanying drawings, inwhich:

Figure 1 is a side elevation of a transformer removed from its casing.

Figure 2 is a fragmentary, sectional View on the line 2--2 of Figure l,such view being drawn to an enlarged scale.

The core structure of the transformer is indicated by the referencecharacter l and it may be a wound type of core structure, for instanceas shown in the patent to Wiegand, No. 2,313,306 of March 9, 1943 forMethod of Making Transfcrmers, such patent being owned by the assigneeof this invention, or it may be formed as a stacked core. Preferably thecore is cruciform in vcross-section so as to approximately lill thecircular window of the conducting winding assembly, such conductingWinding assembly being indicated generally by the reference character 2.This conducting winding assembly may be wound in any suitable manner,for instance, as shown in the above noted patent, and may comprise aninner circular insulating shell'3 on which the two windings 4 and 5 ofthe transformer are carried.

During winding of the transformer, insulating spacing members of wood orother suitable material as indicated by the reference characters 6 and'l may be positioned as shown in detail in Figure 2. It is to be notedthat the spacing members are so arranged, as shown in Figure 2, thatonly one spacing member is positioned in each layer and that thesuccessive spacing members are radially spaced as Well ascircumferentially spaced. Also if desired one group of spacing members,for instance the spacing members l may be located on one side of thewinding and another group of spacing members, for instance the spacingmembers l, may be located on the other side of the winding. In additionto this, a larger or a smaller number of spacing members could beemployed throughout the entire winding, if desired, or found necessaryfor the particular design or size oi transformer employed.

Under all conditions, it is to be understood that it is contemplatedthat the overlying layer of the winding located outside of a spacingmember becomes tangent to the underlying layer before another spacingmember is positioned, even if a plurality of spacing members areemployed for any given layer. However, in the particular formY of theinvention chosen for illustration only a single spacing member has beenshown for a single layer.

By following the construction outlined above and illustrated,particularly in Figure 2, it will be seen that the spacing members arermly anchored in place and are held in their vertical y position at alltimes against accidental displacement either during assembly orinstallation or during use of the transformer. lfhere is no chance of aspacing member shifting and blocking any of the ducts as has heretoforebeen the case. Instead each spacing member is irmly underlying layer oneach side of the spacing'- member, thus precluding shifting'of thespacing-f member.

The spacing members eXtend'beyond-'theupper and lower edges of theWinding asV shown in Figure 1.

It will be seen that each spacingmember is so arranged that it providestwo ducts for the circulation of the cooling oil o r other mediumV andthat it is impossible for the spacing members to'shiftand block theducts:

It' will be seen that the construction isi veryA simple and does notmaterially. increase the bulkiness of the winding assembly.

It is distinctly understood that although the invention hasl beenrdescribed asy primarily intended for transformer construction, thatnevertheless it could be followed for any type of 'electromagneticwinding Where cooling ducts are employed.

Although. this invention has been described inconsiderable detail, itisto ber understood that such description is intended as illustrativerather than limiting,` asthe-invention may be variously embodied and is-to be interpreted as claimed.

Iv claim:

1. In an electromagnetic device, a winding having a plurality of layers,and a plurality of longitudinally extending spacing membersr lo catedbetween successive'layers with each successive spacing memberspacedcircumferentially and radially from-every` other spacing membereci to form a series of pairs of ducts, each individual pair of ductsbeing adjacent one spacing member only and being remote from allotherspacing members.

2. In a transformer construction, a core having at least one leg, aWinding assembly having aV pair ofzwindings surrounding such leg andconstituting primary and secondary windings with each winding having aplurality of layers, and at least two -series of longitudinallyextending spacing members circumferentially spaced with reference tothe; windingVv assembly with one series of spacing members locatedbetween successive layers 'of' the primary Winding and the other seriesof spacing members located between successive layers ofthe secondarywinding and withthe.` two series spaced circumferentially from eachother.

andwith each spacing member circumierentially spaced from everyf otherspacing member to form a series of pairs of ducts, each individual pairof ducts being adjacent one. spacing member only and being remote fromall other spacing members and with any overlying layer of windingtangentto an underlying layer of-Wind- A ing` adjacent eaclrspacing member;

EDWIN A. LINK. .t

REFERENCES: CITED The following references' are of 'record' in the leoflth' patent:

UNITED STATES v PATENTS Number Name Date 829,780 Hall Aug. 28, 19061,411,619 Frank Apr. 4, 1922 2,142.2;0'375 Paluev June-10, 1947'

